Air cooled internal combustion engine



May 23, 1933.

E. s. MARKS 1,910,346 AIR COOLED INTERNAL COMBUSTION ENGINE Filed April 29, 1951 3 Sheets-Sheet l INVENTOR.

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AIR COOLED INTERNAL COMBUSTION ENGINE Filed April 29, 1931 5 Sheets-Sheet 2 INVENTOR.

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AIR COOLED INTERNAL COMBUSTION ENGINE Filed April 29, 1931 3 Sheets-Sheet 3 I N VEN TOR.

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Patented May 23, 1933 Uni'ran s'm'rns rArnnr-orrica EDWARD S. MARKS, F SYRACUSE, NEYV YORK, ASSIGNOE -TO FRANKLIN DEVELOP- MENT CORPORATION, OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK AIR COOLED INTERNAL COMBUSTION ENGINE Application filed April 29,

This invention relates to air cooled internal combustion engines, particularly air cooled engines in which the cylinders are in line, and has for its object, an arrangement and mounting of the support for the rocker arms of the valve operating mechanism, whereby a substantially constant clearance is maintained between the rocker arms and the stems of the intake and exhaust valves, and

between the rocker arms and the push rods operating them. Other objects will appear throughout the specification. V i

The invention consists in the novelfeatures and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings, in which like characters designate corresponding parts in all the views.

Figure 1 is a fragmentary plan view, parts being omitted, of an in line engine embodying my invention.

Figure 2 is an enlarged fragmentary elevation of the cylinder and associated parts.

Figure 3 is a sectional view taken approximately on line 33, Figure 1, parts being omitted.

' Figure 1 is a fragmentary sectional view taken on line 44, Figure 1.

The engine in this application is similar in a general way to that of my application, Sr. No. 336,242, filed January 30, 1929, and differs therefrom in the so-called compensating stud arrangement, and in the modification 135 of'the flanging of the head.

I have here shown the invention as embodied in a multi-cylinder in line type of engine.

This invention comprises generally, a

rocker arm support mounted above the cylinder head and secured at its opposite ends respectivelyto the cylinder head and to a part of theengine colder than the head and cylinder barrel, so that the support varies as the engine heats up, and a compensating stud for securing the intermediate part of the support to the head and varying the warping action thereofythe stud being located 0 adjacent the pivot of the exhaust valverocker arm.

support and hence, the leveL f th Support 1931. Serial No. 533,733.

1 designates the cylinder bar-rel, and-2. 1m elongated detachable head formed with an internal compression chamber 3 of greater diameter than the bore of the cylinder barrel in order to permit larger intake and exhaust;55 valves. The head is formed of a metalhaving a greater heat conductivity thancast iron, as aluminum alloy. It is provided with intake and exhaust ports 4, 5, having passages 6,71eadingtherefrom upwardly and laterallywo through opposite sides of the cylinder-head, these passages 6, 7, communicating respectively with suitable intake and exhaust manifolds. I

8 and 9 are respectively intake and exh'aust.=fi5 valves having stems 10 and 11 extending through suitable guides-through the top of the head. The intake valve is .held against its seat by a spring or springs .12 interposed between a spring abutment 13 on the valveslm stem 10 and the bottom ofa recess .l lformed in the top of the head. Likewise, the exhaust valve is held against its seat by a similar spring or springs 15 interposed between an abutment 16 on the exhaust valve stem 11.and..75 the bottom of a recess in the :top of the head.

Both the cylinder barrel and the head a=re formed with horizontally extending heat radiating flanges 17' and 18, the outer end .portion of theintakepassage which is exposed 5 to the outer air being unprovided with heat radiating flanges. The valves areoperated by mechanism including rocker armscoacting with the valve stems 10 and'll, and-these rocker arms are so mounted as to maintain the proper clearance at all engine temperatures. v

20 and 21 designate the rocker farmsiwhich are pivoted respectively'at-22 and 123 to lugs extending upwardly from a-su-pport 2 L in- .termediate of the ends thereof. This support has one end portionioverhanging the :ex-

haust'sideof the 'head'andthe cylinder, and the overhanging end portion is supported from the crankcase by pillars '25, these being" hollow and utilized to enclose the push' rods which operate the rocker arms' The pillars thread into the overhanging portion-of the support, and the amount they'extend intothe can be Varied to suit conditions. The support is locked in its adjusted position relatively to the pillars 25 by suitable lock nuts 26. The end of the support 24 remote from the overhanging portion, that is, the end adjacent the intake valve is secured in position by two fastening members, rods or bolts 27 which preferably extend through the flanges of the head and thread at 28 in the base portion of the head, these rods being also utilized to secure'the head to the barrel of the cylinder, and for this purpose are provided with extensions through openings in the cylinder wall, and into recesses 29 in the cylinder wall, or the flanges thereof in order that nuts 30 may be screwed onto the lower ends of the extensions to secure the head to the cylinder.

7 The rods 27 are provided with shoulders 31 which thrust against an opposing surface on the head, so that when the nuts 30 are tightened, they tighten the head against the barrel of the cylinder. These fastening members or rods 27 are also provided with means for holding the support ofl? the opposing surface of the cylinder head, this means being shown as shoulders 32 located above the top of the cylinder head and thrusting against the bottom surface of the support 24. Nuts 33 screw on the upper ends of the rods against I the upper surface of the support.

'As thus far described, the rocker arm support 24 is secured in position at substantially four corners thereof, and at two of the corners is secured to the head, and at the other two corners to a part other than the cylinder or the head, as the crank case of the engine.

In order to maintain the clearance between the rocker arms and the valve stems at all engine temperatures, a compensating stud 35, Figures 1 and 4, is provided for each support.

7 This stud is located near the axis of the rocker arm 21 for the exhaust valve, and is secured to, or threads into the head at 36 near the level of the exhaust valve 9, it being provided with a shoulder 37 thrusting against an opposing surface of the head, these two surfaces thrusting against each other being located at approximately the level of the exhaust valve 9. The compensating stud also has a shoulder 38 near its upper end thrusting against the lower side of the rocker arm support 24 tohold it off the cylinder head. A nut 39 threads on the upper end of the stud 35 against the .top surface of the support 24.

40 is a screw for securing the head to the cylinder, this screw being arranged in aline- .ment with the compensating stud 35 and threading into the head, and also having a nut 41 at its outer end similar to the nuts 30. The valve stems extend through suitable passages 42 and 43 in the support, and the springs 12 and 15 also extend through said passages. 45 and 46 are push rods for operating the rocker arms 20 and 21 respectively, these, as

before stated, extending through the tubular pillars 25 into the crank case where they are actuated by the cam shaft in the usual manner. The rocker arms and contiguous parts are covered by a suitable cap 50 secured in position in any suitable manner.

By mounting the rocker arm support 24 on the two members or studs 27, and on the tubular pillars 25, and on the compensating stud 35, a practically uniform valve clearance is maintained at all engine temperatures. As the exhaust valve expands under increased temperatures, it rises vertically and would ordinarily take up all tappet clearance and remain open, if it were not for the compensating stud 35 which rises vertically, because of the expansion of the aluminum of the head beneath it. This vertical movement additionallywarps the support adjacent the pivot of the exhaust valve rocker arm and rocks the fulcrum of the exhaust valve rocker arm and thus maintains a nearly constant clearance of the valves.

What I claim is:

1. In an air cooled internal combustion engine, the combination with a cylinder having a head formed with intake and exhaust ports and passages leading therefrom, intake and exhaust valves controlling said ports having stems extending through the top of the head, valve operating means including a support secured at one end on the head, and at its other end to a colder portion of the engine, whereby the support overhangs one side of the cylinder, rocker arms coacting with said stems respectively and pivoted to the support between the ends thereof, and actuating means for the rocker arms, of a compensating fastening member securing the support to the head, said member being located intermediate of the ends of the support where it is mount ed on the head and on said part of the en ine other than the head and adjacent the pivot of the exhaust valve rocker arm.

2. In an air cooled internal combustion engine, the combination with a cylinder having a detachable head formed with intake and exhaust ports and passages leading therefrom, intake and exhaust valves controlling said ports and having stems extending through the top of the head, and valve operating means including a support mounted at one end on the head, andat its other end on a colder part of the engine other than the head,

whereby the support overhangs one side of the cylinder, rocker arms pivoted to the support between the ends thereof, and coacting with said stems respectively, and means for actuating the rocker arms, of fastening memtangular formation, and a compensating stud located intermediate of the support and adJacent the pivot of the exhaust valve rocker 7 arm and extending only into the head.

3. In an air cooled internal combustion engine, the combination with a cylinder having a detachable head formed With intake and exhaust ports and passages leading therefrom, intake and exhaust valves controlling said ports and having stems extending through the top of the head, and valve operating means including a support mounted at one end on the head, and at its other end on a colder part of the engine other than the head, whereby the support overhangs one side of the cylinder, rocker arms pivoted to the support between the ends thereof, and coacting with said stems respectively, and means for actuating the rocker arms, of fastening members located at one end of the support and extending through the head and into the cylinder wall, the support being fastened at its other end to said part of the engine other than the cylinder, said fastening memhere being located substantially at the corners of a rectangular formation, and a compensating stud located intermediate of the support and adjacent the pivot of the exhaust valve rocker arm and extending only into the head, and threading into the head substantially at the level of the exhaust valve seat.

In testimony whereof, I have hereunto signed my name, at Syracuse, in the county of Onondaga, and State of New York, this 15 day of April, 1931.

EDWARD S. MARKS. 

